BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	nation,
	o_year,
	sum(amount) as sum_profit
from
	(
		select
			n_name as nation,
			extract(year from o_orderdate) as o_year,
			l_extendedprice * (1 - l_discount) - ps_supplycost * l_quantity as amount
		from
			part,
			supplier,
			lineitem,
			partsupp,
			orders,
			nation
		where
			s_suppkey = l_suppkey
			and ps_suppkey = l_suppkey
			and ps_partkey = l_partkey
			and p_partkey = l_partkey
			and o_orderkey = l_orderkey
			and s_nationkey = n_nationkey
			and p_name like '%wheat%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                           QUERY PLAN                                                                                            
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=1194718.91..1194723.46 rows=130 width=46) (actual time=105386.930..108657.614 rows=175 loops=1)
   Group Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
   Buffers: shared hit=35618888 read=2175348 dirtied=11329 written=21797
   ->  Sort  (cost=1194718.91..1194719.24 rows=130 width=46) (actual time=105374.910..106536.629 rows=3245475 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 554699kB
         Buffers: shared hit=35618888 read=2175348 dirtied=11329 written=21797
         ->  Hash Join  (cost=66876.19..1194714.35 rows=130 width=46) (actual time=851.407..92475.138 rows=3245475 loops=1)
               Hash Cond: (supplier.s_nationkey = nation.n_nationkey)
               Buffers: shared hit=35618880 read=2175348 dirtied=11329 written=21797
               ->  Nested Loop  (cost=66874.63..1194710.35 rows=130 width=24) (actual time=851.332..89714.682 rows=3245475 loops=1)
                     Buffers: shared hit=35618876 read=2175348 dirtied=11329 written=21797
                     ->  Nested Loop  (cost=66874.19..1194647.34 rows=130 width=24) (actual time=851.302..48799.995 rows=3245475 loops=1)
                           Buffers: shared hit=23232769 read=1561936 dirtied=11264 written=16193
                           ->  Nested Loop  (cost=66873.90..1194605.40 rows=130 width=28) (actual time=851.285..37508.526 rows=3245475 loops=1)
                                 Buffers: shared hit=13478057 read=1561936 dirtied=11264 written=16193
                                 ->  Hash Join  (cost=66873.34..352135.53 rows=430419 width=16) (actual time=851.229..5214.570 rows=432928 loops=1)
                                       Hash Cond: (partsupp.ps_partkey = part.p_partkey)
                                       Buffers: shared hit=63953 read=147527 written=2324
                                       ->  Seq Scan on partsupp  (cost=0.00..250958.00 rows=8000000 width=12) (actual time=0.006..2543.912 rows=8000000 loops=1)
                                             Buffers: shared hit=37917 read=133041 written=1396
                                       ->  Hash  (cost=65522.00..65522.00 rows=108107 width=4) (actual time=850.562..850.562 rows=108232 loops=1)
                                             Buckets: 131072  Batches: 1  Memory Usage: 4830kB
                                             Buffers: shared hit=26036 read=14486 written=928
                                             ->  Seq Scan on part  (cost=0.00..65522.00 rows=108107 width=4) (actual time=0.015..812.630 rows=108232 loops=1)
                                                   Filter: ((p_name)::text ~~ '%wheat%'::text)
                                                   Rows Removed by Filter: 1891768
                                                   Buffers: shared hit=26036 read=14486 written=928
                                 ->  Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem  (cost=0.56..1.95 rows=1 width=24) (actual time=0.015..0.072 rows=7 loops=432928)
                                       Index Cond: (l_partkey = partsupp.ps_partkey)
                                       Filter: (partsupp.ps_suppkey = l_suppkey)
                                       Rows Removed by Filter: 22
                                       Buffers: shared hit=13414104 read=1414409 dirtied=11264 written=13869
                           ->  Index Scan using pk_supplier on supplier  (cost=0.29..0.31 rows=1 width=8) (actual time=0.003..0.003 rows=1 loops=3245475)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9754712
                     ->  Index Scan using pk_orders on orders  (cost=0.43..0.47 rows=1 width=8) (actual time=0.012..0.012 rows=1 loops=3245475)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12386107 read=613412 dirtied=65 written=5604
               ->  Hash  (cost=1.25..1.25 rows=25 width=30) (actual time=0.022..0.022 rows=25 loops=1)
                     Buckets: 1024  Batches: 1  Memory Usage: 10kB
                     Buffers: shared hit=1
                     ->  Seq Scan on nation  (cost=0.00..1.25 rows=25 width=30) (actual time=0.005..0.009 rows=25 loops=1)
                           Buffers: shared hit=1
 Planning time: 31.056 ms
 Execution time: 108714.915 ms
(46 rows)

COMMIT;
COMMIT